Zn-Mg合金的微弧氧化改性研究

Study on Micro-arc Oxidation of Zn-Mg Alloys

研究了微弧氧化电流、Mg含量和氧化时间对Zn-Mg合金的微弧氧化电压和氧化膜层厚度的影响。观察了微弧氧化后的Zn-Mg合金的显微组织,分析其物相组成并测量了微弧氧化样品的耐腐蚀性能。研究结果表明:Zn-Mg合金的微弧氧化电压和氧化膜层厚度随着微弧氧化电流、时间的增加而提高。当Zn-1Mg合金在3A的氧化电流下处理2min后,Zn-1Mg表面的微弧氧化膜孔洞细小而均匀,膜层质量最好,膜厚为98.6μm。微弧氧化后的Zn-Mg合金表面膜层由为ZnO、Zn(OH)2和Zn2SiO4三相组成。耐腐蚀性测试表明,经微弧氧化后Zn-1Mg合金试样的自腐蚀电位最高为-0.4546V和电流密度最低为4.1322×10^-7A·cm^-2。在模拟体液中浸泡45天后,微弧氧化后Zn-1Mg合金失重最少,这说明微弧氧化提高了Zn-1Mg合金的耐腐蚀性能。

The effects of oxidation current,Mg content and oxidation time on micro-arc oxidation voltages and film thickness of Zn-Mg alloys were studied in this paper.The microstructure of Zn-Mg alloy after micro-arc oxidation was observed,and its phase composition and corrosion resistance were analyzed.The results show that the voltage and thickness of the oxidation layers both increase by increasing the oxidation current and time.The oxidation film with the thickness of 98.6μm has better quality and more uniform pores when the Zn-1 Mg sample is oxidated at 3 A for 2 min.XRD analysis shows that the main components of the micro-arc oxidation coating are ZnO,Zn(OH)2 and Zn2SiO4.The corrosion resistance test shows that self-corrosion potential and passive current density of Zn-1 Mg alloys after micro-arc oxidation are-0.4546 V and 4.1322×10^-7 A·cm^-2,which has the least weight loss when immersed in SBF for 45 days.The corrosion resistance of the Zn-1 Mg alloys can be improved by the micro-arc oxidation.